Ghrelin protects against palmitic acid or lipopolysaccharide-induced hepatocyte apoptosis through inhibition of MAPKs/iNOS and restoration of Akt/eNOS pathways.

Abstract Bacground Ghrelin has been shown to exert various biological functions. However, the effect and mechanism of ghrelin on PA- or LPS-induced liver injury remains unknown. Methods Normal human hepatocyte lines (LO2 and 7701) were pretreated with ghrelin (10 −8  M) for 30 min before stimulation with lipopolysaccharide (LPS) or palmitic acid (PA). The proliferation and apoptosis of cells were detected with CCK8, Hoechst staining and flow cytometric analysis. Levels of NO of cell supernatants were examined by enzyme-linked immunosorbent assay (ELISA). The protein levels and mRNA of target genes of endothelial NOS (eNOS) and inducible NOS (iNOS) were measured by western blotting, immunofluorescence and quantitative real-time polymerase chain reaction (qRT-PCR). The expression of Bax, Bcl2, caspase 3, p-Akt, p-P38 and p-JNK were detected by western blotting. Results Results of CCK8, Hoechst staining and flow cytometric analysis showed that ghrelin-pretreatment attenuated LPS- or PA- induced cellular proliferation inhibition and apoptosis induction. ELISA results revealed that ghrelin pretreatment reduced levels of NO of cell supernatants (P  Conclusions Ghrelin pretreatment attenuated LPS- or PA-induced hepatocyte apoptosis, which may least partly via inhibition of mitogen-activated protein kinases (MAPKs)/iNOS and restoration of Akt/eNOS pathways.